It is planned to continue to complete our collaborative studies in normal volunteers and obese subjects of the endocrine and thermogenic response to overfeeding fat, carbohydrate, and protein. It is planned to study the effects of caloric restriction with and without ketosis on the capacity for high intensity and endurance exercise. Endocrine response, metabolic substrates, and muscle glycogen will be measured. BIBLIOGRAPHIC REFERENCES: Experimental obesity, dietary-induced thermogenesis, and their clinical implications. E.A.H. Sims. Clinics in Endocrinology and Metabolism - Vol. 5, No. 2, July 1976. Experimental obesity in man: VII. Metabolic rate in relation to dietary intake. R.F. Goldman, M.F. Haisman, G. Bynum, L.B. Salans, E. Danforth, Jr., E.S. Horton and E.A.H. Sims. Chapter 21 in Obesity in Perspective. Fogarty International Center Series on Preventive Medicine. Washington: U.S. Government Printing Office. 1976. p.165.